There are a number of devices on the market that are capable of automatically or semi-automatically delivering doses of medicament, where these devices comprise a number of inter-acting components for obtaining the desired functions.
One type of such delivery devices is an injector capable of delivering doses of medicament, having functions such as penetration of the patient's skin and a subsequent injection of medicament. One such device is for example disclosed in the document EP 1349590, comprising an activation mechanism in the form of a button placed at its distal end. The button may only activate the mechanism if the front end of the device is pressed against an injection site. When done so and the button is pressed, the penetration mechanism inside the injector is released whereby the needle is pushed into the body of the patient. After this, the injection is performed.
When the injection is completed, the patient withdraws the injector with the needle from the injection site, whereby a needle shield is pushed forward until it surrounds the needle and is then locked.
With an injector of the above described type there is often a desire for the user to know when the injection is completed and it is safe to remove the injector. A few solutions of informing the user of the status of the injection have been developed.
U.S. Pat. No. 6,221,046 describes an injection device having an “end of injection click” including an extension on a flexible tab of a dose dial mechanism. The tab with the extension falls into a groove in the housing, causing an audible click at the end of injection. US 2004/0097883 discloses a similar end of injection click solution.
However, even if some solutions have been presented regarding informing a user of a medical delivery device, there is still room for improvements, especially regarding the delivering step of a medical delivery device.